[make-initrd] [PATCH v6 06/22] bootchain-waitdev: improving the logic of the step

[Leonid Krivoshein]

1. Breaks the loop when the specified device is actually found.
2. Send a message to the log about the detection of the specified device.
3. Also save the device's real node name to the DEVNAME file.

Signed-off-by: Leonid Krivoshein <klark.devel at gmail.com>
---
 features/bootchain-core/README.md                     | 6 ++++++
 features/bootchain-waitdev/data/lib/bootchain/waitdev | 9 ++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/features/bootchain-core/README.md b/features/bootchain-core/README.md
index 0ccacd9..7f12f1d 100644
--- a/features/bootchain-core/README.md
+++ b/features/bootchain-core/README.md
@@ -49,6 +49,12 @@ us to optimize fill in `initramfs` only which we are need.
 
 - Modularity: loading methods are initially separated from the common
   code and daemon.
+- Allows you to work with shorter and more familiar paths to special files
+  devices thanks to the use of `DEVNAME` along with `dev`.
+
+Despite the differences, `chaind` is backward compatible with previously
+written steps for the `pipelined` daemon and does not require changes for
+configurations with `root=pipeline`.
 
 ## External elements of the bootchain (steps-scripts)
 
diff --git a/features/bootchain-waitdev/data/lib/bootchain/waitdev b/features/bootchain-waitdev/data/lib/bootchain/waitdev
index bc81673..60464d9 100755
--- a/features/bootchain-waitdev/data/lib/bootchain/waitdev
+++ b/features/bootchain-waitdev/data/lib/bootchain/waitdev
@@ -13,11 +13,14 @@ while [ -n "$devspec" ]; do
 		read -r devfile < "$envfile" ||:
 
 		if [ -n "$devfile" ]; then
-			if [ ! -e "$destdir/dev" ]; then
-				target="$(readlink-e "$devfile")"
+			target="$(readlink-e "$devfile" 2>/dev/null ||:)"
+
+			if [ -b "$target" ] || [ -c "$target" ]; then
+				message "target device found: $target"
+				printf '%s\n' "$target" > "$destdir/DEVNAME"
 				run cp -a -- "$target" "$destdir/dev"
+				break
 			fi
-			break
 		fi
 	fi
 
-- 
2.24.1